13. Applications and implications

The task for this week was to define a potential final project and outline the components it will consist of. The aim from the beginning was to learn more about CAD, electronics design and embedded programming and to develop a fun device.

What will it do?

• As outlined in final project, I would like to create a moveBot that (forcefully) reminds the user to move. The bot also serves as a reminder to take regular (preferably standing) breaks for those who spend most of their working time seated. The moveBot will consist of different elements:
  • a timer that reminds the user to get up and move
  • infrared proximity sensors that detect motion
  • motors that move when motion is detected (activated by the IR sensors)
  • LEDs activated by the servos that guide the users and indicate when a task is complete.

Who’s done what beforehand?

• So far, the tasks from previous weeks have not been related to the final project, as it was more of exploration and learning about the different processes. In Input devices, I tested a PIR sensor that is a potential input device for the final project. In Output devices, using the same board made in the previous week, I tested RGB LEDs and a servo motor which will most likely be used in the final project. Also I started working on the main board for the project that incorporates all the main elements in Output devices week..

• Related online examples include:

  • Make an Arduino Timer
  • PIR motion sensor
  • Simple IR Proximity Sensor With Arduino
  • Arduino Servo Motors
  • Simple RGB LED Light with Fade

• From Fab Academy:

  • Self-playing drum
  • Lamp bot
  • Cap counting attachment
  • Pomodoro productivity owl

What will you design?

• A device that aims to limit prolonged sitting. See what will it do above, what parts and systems will be made, and what processes will be used below.
• The main element will be the PCB board.
• A casing for this main board, a holder for the servos, a heart-shaped figure that will be attached to the moveBot
• A logo to be Vinyl cut.

What materials and components will be used?

• IR proximity sensors
• Servor motors
• Power supply (9V battery)
• Pin Headers
• ATmega 328 /ATtiny44
• LEDs (RGB, Neopixel (perhaps))
• Plywood/MDF, 3D printing material
• Bluetooth module (HC-06)
• Plus many of the other SMD components (resistors, capacitors, resonator, voltage regulator etc.)
• Buzzer
• FTDI HEADER
• PCB for boards
• For 3D printing, I am not yet sure what material I will use, but it will be a small part of the overall project so it’s not so crucial. It could be a casing for the main board for example, and/or a heart-shaped hollow design to be printed in preferably semi-transparent material.

Where will they come from?

• Most of the materials will come from the fab lab inventory and others like the Bluetooth module have to be ordered.

How much will they cost?

Bill of materials

Part	Value	Quantity	Price
PIN HEADER FOR BUZZER	PINHD-2X2-SMD	1	~€0.70
PIN HEADERS FOR IR PROXIMITY SENSORS	PINHD-2X2-SMD	6	~€5
PIN HEADERS FOR SERVOS	PINHD-2X3-SMD	3	€2
PIN HEADERS FOR LEDs	PINHD-2X2-SMD	~2	€1.50
PIN HEADER FOR NEOPIXELS	PINHD-2X3-SMD	1	€0.60
PIN HEADER FOR RGB-LEDs	PINHD-2X2-SMD	~3	€2
PIN HEADER FOR POWER SUPPLY	PINHD-2X2-SMD	1	~€0.70
PIN HEADER FOR BLUETOOTH MODULE	PINHD-2X5-SMD	1	~€1
AVRISP PROGRAMMING HEADER	AVRISPSMD	~4	~0.60
RESISTORS	DIFEERENT VALUES	~20	~€0.20
REGULATOR		~2	~€1
RESONATOR	20 MHz	~2	~€1
CAPACITORS	DIFFERENT VALUES	~4	~€0.80
SMD LEDS	LEDFAB1206	~10	~€1
RGB LEDS		~3	~€1.50
NMOSFET		~3	~€3
MICROCONTROLLER	ATMEGA328P-AU	1	~€3
BLUETOOTH MODULE	HC-06	1	~€10
SERVO MOTORS		~3	~€22
FTDI HEADER(?)		1	~€3
IR PROXIMITY SENSORS AND DIODES		~6	~€5
BUZZER/SPEAKER		~2	~€2
M/M and F/F Jumper Wires		~40	~€4
Total			~€72

The cost of 3D printing material and plywood/MDF is not yet calculated as I am not yet sure what material I will use.

What parts and systems will be made?

• The PCB board (which includes Pin headers for the different components and LEDs) and maybe separate IR motion sensor boards (if not integrated in the main PCB board)
• Design of the actual moveBot consisting of movable parts controlled by servo motors, IR sensors that act as inputs and activate the servos and LEDs that indicate the progress or when a task is complete.
• Casing for the main board, servo holder and object attach to the the servo rotating gear.

What processes will be used?

• 2D design and Vinyl cutting- In CAD week, I designed a logo for the final project that will be Vinyl cut.
• 3D design and printing for housing the manufactured PCBs (and maybe the servo holder and a rotating wheel)
• Laser Cutting and/or CNC machining for parts of the main MoveBot
• Electronics design and production for the main board
• Embedded programming to control the different components (sensors, motors and LEDs)
• Network and Communications: wireless communication via Bluetooth

What questions need to be answered?

The main question to be answered is the structure of the device and how to design it taking into consideration the placement of components (LEDs, Servos and IR proximity sensors) or overall packaging. As I plan to use a Bluetooth module, how to automate bluetooth pairing and perhaps control of the components. How to program the timing of reminders? What kind of output to display and from which LEDs?

How will it be evaluated?

• Whether it meets the stated objectives of providing a trigger (either sound, lights or both) to move and clear indication of the required tasks (IR sensors that detect movement which activate the servo motors sequentially and after certain number of movements LEDs turn on).
• As a minimum, the IR sensors should detect motion that activates the servos and the LEDs should either turn on when the whole range of motions are done or after 1 round (interaction with either 2 or 3 servos).
• Bonus points if I manage to setup Bluetooth connectivity and be able to program and control it wirelessly.
• At this stage, this will be a minimum viable product just to test the functionality and perhaps use it for research. Later, depending on how this turns out, I might improve it and fabricate a product for real use.